Media type: E-Article Title: The cause and influence of sequentially assembling higher and lower deacetylated chitosans on the membrane formation of microcapsule Contributor: Zheng, Guoshuang; Zheng, Huizhen; Xie, Hongguo; Liu, Xiudong; Yu, Weiting; Ma, Xiaojun imprint: Wiley, 2016 Published in: Journal of Biomedical Materials Research Part A Language: English DOI: 10.1002/jbm.a.35562 ISSN: 1549-3296; 1552-4965 Keywords: Metals and Alloys ; Biomedical Engineering ; Biomaterials ; Ceramics and Composites Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>Alginate‐chitosan (AC) microcapsules with desired strength and biocompatibility are preferred in cell‐based therapy. Sequential assembly of higher and lower deacetylated chitosans (C<jats:sub>1</jats:sub> and C<jats:sub>2</jats:sub>) on alginate has produced AC<jats:sub>1</jats:sub>C<jats:sub>2</jats:sub> microcapsule with improved membrane strength and biocompatibility. In this article, the assembly and complexation processes of two cationic chitosans on anionic alginate were concerned, and the cause and influence of sequentially assembling chitosans on AC<jats:sub>1</jats:sub>C<jats:sub>2</jats:sub> microcapsules membrane formation were evaluated. It was found that C<jats:sub>1</jats:sub> complexation was the key factor for deciding the membrane thickness of AC<jats:sub>1</jats:sub>C<jats:sub>2</jats:sub> microcapsule. Specifically, the binding amount of C<jats:sub>2</jats:sub> positively related to the binding amount of C<jats:sub>1</jats:sub>, which suggested the first layer by C<jats:sub>1</jats:sub> complexation on alginate had no obvious resistance on the sequential cationic C<jats:sub>2</jats:sub> complexation. Further analyses demonstrated that outward migration of alginate molecules and inward diffusion of both chitosans under electrostatic interaction contributed to the sequential coating of C<jats:sub>2</jats:sub> on first C<jats:sub>1</jats:sub> layer. Moreover, C<jats:sub>2</jats:sub> complexation through the surface to inner layer of membrane helped smoothen the first layer by C<jats:sub>1</jats:sub> complexation that displayed a synergy role on the formation of AC<jats:sub>1</jats:sub>C<jats:sub>2</jats:sub> microcapsule membrane. Therefore, the two chitosans played different roles and synergistically contributed to membrane properties that can be easily regulated with membrane complexation time. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 257–263, 2016.</jats:p>